#include <bits/stdc++.h>

#define DBG(x) cerr << #x << " = " << x << endl;

const int maxn = 1e3+5;

using namespace std;

typedef long long LL;

int n;

struct node{

    int id,val;

}a[maxn];

bool cmp(node a,node b){

    return a.val > b.val;

}

vector<pair<int,int> >vec;

int main(){

    scanf("%d",&n);

    int sum=0;

    for(int i=1;i<=n;i++){

        scanf("%d",&a[i].val);

        sum+=a[i].val;

        a[i].id=i;

    }

    if(sum < (n-1)*2){puts("NO");return 0;}

    sort(a+1,a+1+n,cmp);

    int pos=n,cnt=0;

    for(int i=1;i<=n;i++){

        if(a[i].val > 1)cnt++;

        else{pos=i-1;break;}

    }

    for(int i=2;i<=pos;i++){

        vec.push_back({a[i].id,a[i-1].id});

        a[i].val--;

        a[i-1].val--;

    }

    int ans=pos-1;

    if(pos != n){

        vec.push_back({a[1].id,a[pos+1].id});

        a[1].val--;

        a[pos+1].val--;

        ans++;

    }

    int flag=0;

    for(int j=pos+1;j<=n;j++){

        for(int i=pos;i>=1;i--){

            if(a[j].val == 0)break;

            if(a[i].val == 0)continue;

            vec.push_back({a[j].id,a[i].id});

            a[j].val--;

            a[i].val--;

            if(flag == 0 && i == pos){flag=1;ans++;}

        }

    }

    printf("YES %d\n",ans);

    printf("%d\n",vec.size());

    for(int i=0;i<vec.size();i++){

        printf("%d %d\n",vec[i].first,vec[i].second);

    }

    return 0;

}

#include <bits/stdc++.h>

#define DBG(x) cerr << #x << " = " << x << endl;

const int maxn = 5e5+5;

using namespace std;

typedef long long LL;

LL n,k,a[maxn];

LL pre[maxn],suf[maxn],expre[maxn],last[maxn];

int main(){

    scanf("%I64d%I64d",&n,&k);

    for(int i=1;i<=n;i++){

        scanf("%I64d",&a[i]);

        if(a[i] == k)pre[i]++,suf[i]++;

    }

    for(int i=1;i<=n;i++)pre[i]+=pre[i-1];

    for(int i=n;i>=1;i--)suf[i]+=suf[i+1];

    for(int i=1;i<=n;i++){

        expre[i]=pre[i-1]+1;

        int pos=last[a[i]];

        if(pos)expre[i]=max(expre[i],expre[pos]+1);

        last[a[i]]=i;

    }

    LL ans=0;

    for(int i=1;i<=n+1;i++)ans=max(ans,expre[i-1]+suf[i]);

    printf("%I64d\n",ans);

    return 0;

}

#include <queue>

#include <cstdio>

#include <cstring>

#include <iostream>

#include <algorithm>

using namespace std;

typedef long long LL;

const LL inf  = 1e18;

const LL maxn = 1e5+5;

struct Dinic {

    static const LL maxn = 1e5+5;

    static const LL maxm = 4e5+5;

    struct Edge {

        LL u, v, next, flow, cap;

    } edge[maxm*2];

    LL head[maxn], level[maxn], cur[maxn], eg;

    void addedge(LL u, LL v, LL cap) {

        edge[eg]={u,v,head[u],0,cap},head[u]=eg++;

        edge[eg]={v,u,head[v],0,  0},head[v]=eg++;

    }

    void init() {

        eg = 0;

        memset(head, -1, sizeof head);

    }

    bool makeLevel(LL s, LL t, LL n) {

        for(int i = 0; i < n; i++) level[i] = 0, cur[i] = head[i];

        queue<LL> q; q.push(s);

        level[s] = 1;

        while(!q.empty()) {

            int u = q.front();

            q.pop();

            for(LL i = head[u]; ~i; i = edge[i].next) {

                Edge &e = edge[i];

                if(e.flow < e.cap && level[e.v] == 0) {

                    level[e.v] = level[u] + 1;

                    if(e.v == t) return 1;

                    q.push(e.v);

                }

            }

        }

        return 0;

    }

    LL findpath(LL s, LL t, LL limit = inf) {

        if(s == t || limit == 0) return limit;

        for(LL i = cur[s]; ~i; i = edge[i].next) {

            cur[edge[i].u] = i;

            Edge &e = edge[i], &rev = edge[i^1];

            if(e.flow < e.cap && level[e.v] == level[s] + 1) {

                int flow = findpath(e.v, t, min(limit, e.cap - e.flow));

                if(flow > 0) {

                    e.flow += flow;

                    rev.flow -= flow;

                    return flow;

                }

            }

        }

        return 0;

    }

    LL max_flow(int s, int t, int n) {

        LL ans = 0;

        while(makeLevel(s, t, n)) {

            LL flow;

            while((flow = findpath(s, t)) > 0) ans += flow;

        }

        return ans;

    }

} di;

LL n,m,st,en;

LL a[maxn];

int main() {

    di.init();

    scanf("%I64d%I64d",&n,&m);

    st=0,en=n+m+1;

    for(int i=1;i<=n;i++){

        scanf("%I64d",&a[i]);

        di.addedge(i,en,a[i]);

    }

    LL sum=0;

    for(int i=1;i<=m;i++){

        LL x,y,z;

        scanf("%I64d%I64d%I64d",&x,&y,&z);

        di.addedge(st,i+n,z);

        di.addedge(i+n,x,inf);

        di.addedge(i+n,y,inf);

        sum+=z;

    }

    printf("%I64d\n",sum-di.max_flow(st,en,en+1));

    return 0;

}